1984 Doner Conversion

[Turtleman]

Since I've read allot of the build topics and the FAQ. Its easy to see a large number of people are adding 70's suspension to their trucks,, All for good reasons,,, Maybe I'm off camber here,, but wouldn't it be true that the later models might have a better engineered suspension,, just considering technological changes?
The Objective
To replace the entire 66 suspension front and rear
Replace shoe brakes, front and rear.
Replace the entire steering system.

I think I'm getting a little to old to ride around on the 66 suspension anymore, and the lack of a power tilt steering is just getting tiresome... when I was younger and just out of the Marines I didnt mind all that.. but I've always told people "its not the age,, its the mileage,,," and I have Allot of miles!.

Has anyone on these forums used a 1984 to convert before?

If So was there any issues with swapping out the rear springs to a leaf spring and did it change the height any?.. I like the height I have now but it wont carry very much.
I'd like to use the front suspension without changing out the cross member but I dont know what I'm walking into on any of this. I'd like to keep all this as simple as I can and I really dont like bits and pieces patch jobs, I like to change a component out and keep the "whole" component the same so if something goes on later its all one make/year to deal with. The brakes are as much a safety issue as anything, I have a set of "Prime 15 inch rims" now and I already know I'll have to buy a 6 lug disk but I've always wondered if the caliper would clear the inside rim.
Any Opinions?